These days, it seems that I write mostly about immune checkpoint blockade drugs, or some other new immunotherapy treatment for cancer. This post is no different—it covers PD-L1, a protein that is at the center of clinical decisions for selecting patients who are likely to benefit from treatment with an anti-PD-1 or anti-PD-L1 drug. Continue reading…

“Roche (SIX: RO, ROG; OTCQX: RHHBY) today announced that in the large pivotal Phase II study, BIRCH, the investigational cancer immunotherapy atezolizumab (MPDL3280A; anti-PDL1) met its primary endpoint and shrank tumours (objective response rate; ORR) in people with locally advanced or metastatic non-small cell lung cancer (NSCLC) whose disease expressed PD-L1 (Programmed Death Ligand-1). The study showed the amount of PD-L1 expressed by a person’s cancer correlated with their response to the medicine. Adverse events were consistent with what has been previously observed for atezolizumab.

“ ‘We are encouraged by the number of people who responded to atezolizumab and maintained their response during the study, which is particularly meaningful for people who had received several prior treatments,’ said Sandra Horning, M.D., Chief Medical Officer and head of Global Product Development. ‘We plan to present results at an upcoming medical meeting and will discuss these data as well as results from our other lung cancer studies with health authorities to bring this medicine to patients as quickly as possible.’ “

“Jason J. Luke, MD, FACP, assistant professor of medicine, The University of Chicago, discusses the efficacy of PD-1/PD-L1 inhibitors in melanoma. The combination of these inhibitors, nivolumab and ipilimumab, was used to treat patients with previously untreated, unresectable or metastatic melanoma, in the Checkmate 069 study.

“Luke says PD-L1 is very complex and difficult when developing immunohistochemical assays. Since several pharmaceutical companies conduct different assays that test various things, a particular patient may be positive in one case, but not in another. For this reason, patients become very confused.

“Luke also mentions that there is no validated method across the board, so it is difficult to determine the next steps going forward.”

Of all cancer types, melanoma is the most investigated in terms of its potential to be treated through immune system-based approaches. More immunotherapy drugs are approved for melanoma than for any other type of cancer, and more are in development. Recent additions to the immunotherapy arsenal are the ‘anti-PD-1’ immune checkpoint blockade drugs pembrolizumab (Keytruda) and nivolumab (Opdivo). Continue reading…

“Rita Nanda, MD, assistant professor of Medicine, associate director, Breast Medical Oncology, The University of Chicago Medicine, discusses the efficacy of pembrolizumab and atezolizumab for the treatment of patients with metastatic triple-negative breast cancer (TNBC).

“Response rates seen with the two immunotherapy agents in two separate clinical trials in a heavily pretreated metastatic population was slightly under 20%, Nanda explains. This is significant due to how heavily pretreated these patients were, she adds.

“Furthermore, these responses were found to be durable and lasted up to 40 weeks. Both pembrolizumab and atezolizumab were shown to be well-tolerated. Patients experienced low-grade toxicities that were easily managed.”

The biggest news in melanoma treatment from the 2015 American Society of Clinical Oncology (ASCO) annual meeting was undoubtedly the report from a large, phase III, randomized clinical trial that compared a combination of two ‘checkpoint inhibitor’ drugs—nivolumab (Opdivo) and ipilimumab (Yervoy)—with the same drugs given alone.

“An immunotherapy combination for untreated melanoma reduced the risk of death or progression by more than half as compared with a drug currently used as a standard of care, a large randomized trial showed.

“Patients treated with nivolumab (Opdivo) and ipilimumab (Yervoy) had a median progression-free survival (PFS) of 11.5 months compared with 2.9 months for ipilimumab alone and 6.9 months with nivolumab monotherapy. Median PFS with the combination and with nivolumab alone increased to 14 months — more than four times greater than the PFS of patients who received only ipilimumab — among patients whose tumors tested positive for programmed death receptor ligand 1 (PD-L1), the target of nivolumab.

“The PFS improvement came at a price of increased toxicity, as grade 3/4 adverse events occurred twice as often with the combination as with ipilimumab monotherapy, but even patients who discontinued treatment because of side effects did better with the combination, as reported here at the American Society of Clinical Oncology meeting.”

“The phase II study randomized patients with NSCLC to atezolizumab (MPDL3280A) or docetaxel in the second- or third-line setting. Patients who were administered the anti-PD-L1 agent were treated until practitioners determined there was no longer a benefit, Spira says. Patients in the docetaxel arm were treated until disease progression.

“At the interim analysis, which is not yet final, there was improved survival with atezolizumab. A correlation was also found between PD-L1 expression and efficacy of the drug. A phase III study is ongoing. Results from this study could also potentially identify a biomarker, Spira adds.”

“Drugmakers including Bristol-Myers Squibb Co and Merck & Co are testing which patients will most benefit from new cancer treatments based on a protein found in their tumors, but that guide, known as a biomarker, may be too unreliable, researchers and health experts said.

“Bristol’s Opdivo and Merck’s Keytruda are both therapies designed to block a protein known as Programmed Death receptor (PD-1) that tumors use to evade the body’s natural defenses. Competitors Roche Holding, AstraZeneca and Pfizer also have similar drugs in an earlier stage of development. The drugmakers are conducting clinical trials that test patient tumors for a related protein called PD-L1.

“The new drugs are mainly aimed at patients with so-called solid tumors suffering from diseases including lung cancer and liver cancer. Lung cancer, the most common type, claims 1.8 million new cases each year worldwide. Sales of drugs to block PD-1 could reach $33 billion a year by 2022, according to Morningstar.”